alienator vs unpleasant person

alienator and unpleasant person both are nouns.

Word	Noun	Adjective	Verb	Adverb
alienator	Yes	No	No	No
unpleasant person	Yes	No	No	No

As nouns, unpleasant person is a hypernym of alienator; that is, unpleasant person is a word with a broader meaning than alienator:

alienator: an unpleasant person who causes friendly people to become indifferent or unfriendly or hostile
unpleasant person: a person who is not pleasant or agreeable

Other hypernyms of alienator include disagreeable person.

alienator (noun)	unpleasant person (noun)
an unpleasant person who causes friendly people to become indifferent or unfriendly or hostile	a person who is not pleasant or agreeable